How reliable are rust converters?

[Machal]

I have the Mar-Hyde rust converter https://10carbest.com/best-rust-converters . This isnt a showroom restoration so I was planning to wire wheel the entire underside of the car, spray the rust converter, then epoxy, then bedliner as undercoating. Just curious if anyone has ever used MarHyde or POR15 and painted over it. How did it turn out?

[smario259]

I use to scrape the rust to the metal, use rust eliminator, then clean it off. Repair with resin and fiberglass if the sheetmetal is seriously attacked, then if the area is prone to damage from stone and gravel I sand and cover with one layer of fiberglass cloth and clear resin. This layer will hopefully not let the stones get to the metal. Then two coats of POR15. No paint sticks to POR15.